Probe cards are typically used in the testing of integrated circuit (IC) devices. Due to their design, probe cards are particularly advantageous for testing entire semiconductor wafers to detect any manufacturing defects before they are diced and packaged. For example, a probe card is typically formed from a printed circuit board (PCB) having a number of electrical contact elements and/or traces disposed thereon to connect to a testing apparatus. The PCB is connected to a probe head having a number of pins that are brought into contact with a device under test (DUT) to facilitate the transmission of electrical signals to and from the DUT. Accordingly, the probe card acts as an interface between the testing apparatus and the DUT.
Because the probe head serves as the primary interface with the DUT, the pitch (i.e., spacing between the pins) of the probe head must be very small in order to properly align with corresponding contact pads of the DUT. On the other hand, the electrical traces on the PCB are generally coarser and spaced further apart to be more easily connected to the testing apparatus (e.g., automatic test equipment or “ATE”). Accordingly, many probe cards include a space transformer disposed between the PCB and the probe head to interface the pins of the probe head with the electrical traces on the PCB. A space transformer may be made of a multi-layer structure (such as a multi-layer organic (MLO), multi-layer ceramic (MLC), or multiple layers of substrate) having a plurality of transmission paths formed therein to connect the probe head to the PCB. The transmission paths of the space transformer are typically soldered to pads corresponding to the electrical traces on the PCB. This ensures a stable and/or secure electrical connection between the space transformer and the PCB. However, the soldering also makes it difficult to take apart the probe card should the space transformer need to be replaced.
The stress from repeated testing may cause one or more components of the probe card to break or malfunction, and therefore need to be replaced. Accordingly, there is a need for a probe card assembly with interchangeable components. More specifically, there is a need for a low cost means of detaching (and attaching) the individual components that does not require desoldering (or soldering) of the electrical contacts (e.g., which can be an expensive and time-consuming process).
Like reference numerals refer to corresponding parts throughout the drawing figures.